We are overhauling our Files tab as a part of another product launch which will help address the file organization feedback behind the need for folders. You can get access by having your Asana admin sign up for our Notes Early Access release: 📝 Improved Notes Early Access Program: Share Your Notes, Privately and Publicly!
I’ve added the feedback about file name truncation to our backlog to be prioritized as I can completely understand how that makes it difficult to manage your files in Asana!